Báo cáo khoa học: " The Work on Machine Translation in the Soviet Union" pot

Rozentsveig, First Moscow State Pedagogical Institute of Foreign Languages, Moscow, USSR Problems of machine translation have been investigated in the Soviet Union since 1955.1 A number

[Mechanical Translation, vol.5, no.3, December 1958; pp 95-100]

The Work on Machine Translation in the Soviet Union *

Fourth International Congress of Slavicists Reports, Sept 1958

V Yu Rozentsveig, First Moscow State Pedagogical Institute of Foreign Languages, Moscow, USSR

Problems of machine translation have been

investigated in the Soviet Union since 1955.1 A

number of groups are carrying out theoretical

and experimental work in the area of machine

translation

In the Institute of Precision Mechanics and

Computer Technology of the Academy of

Sciences of the USSR (ITM and VT) dictionaries

and codes of rules (algorithms) have been com-

piled for machine translation from English, Chi-

nese, and Japanese into Russian; and a German-

Russian algorithm is being worked out Experi-

mental translations of individual passages have

been made 2 In the work of the ITM and VT

group there is a marked striving for the rapid

achievement of immediate, practical results

The efforts of this group are directed not so

much toward a theoretical comprehension of

the general problem of machine translation as

toward a careful, detailed investigation of lin-

guistic material, especially lexical Diction-

ary routines, routines for analysis of the sen-

tence in the source language, and routines for

the synthesis of the sentence in the target lan-

guage are being compiled in the ITM and VT on

the basis of traditional methods of describing a

language

* Translated by Lew R Micklesen, Depart-

ment of Far Eastern and Slavic Languages and

Literature, University of Washington, De-

cember 1958

1 The idea of machine translation was advanc-

ed even in the 30's by the inventor-technician,

P P Smirnov-Troyansky

An essentially different course is being fol- lowed by the group working in the Steklov Mathe- matical Institute of the Academy of Sciences (MIAN) The problem of machine translation is being examined here as part of the larger prob- lem of the automation of thought processes The directors of this group regard the effective prac- tical realization of machine translation only as the result of profound theoretical research in the area of mathematics and linguistics

In MIAN three algorithms have been elabo- rated: French-Russian, English-Russian, and Hungarian-Russian 3 During the compilation of the first of these algorithms in 1955-56, the workers in this group proceeded empirically,

i e they extracted the rules for the transla- tion of each word from a comparative analysis

of French texts and their Russian translations

In the elaboration of the English-Russian algo- rithm, the MIAN group posed for themselves

a more complex problem determination of the correspondences between the grammatical structures of two languages The posing of such a problem was partially conditioned by the nature of the relationships of the English and Russian languages: although it was possible to build the analysis of a sentence on a morpholo- gical basis in translating a French mathematical text into Russian, such a method did not seem rational to the MIAN group in the case of Eng- lish-Russian translations of similar texts The problem was also partially conditioned by the theoretical goal of the director of the group Professor A A Lyapunov: to work out strictly formal methods of describing languages in or- der to attain gradual automation of the whole process of machine translation

2 I K Bel'skaya, "Concerning Certain Gen-

eral Problems of Machine Translation," Ab-

stracts of the Conference on Machine Transla-

tion, Moscow, 1958, pp 10-14, (hereafter re-

ferred to as Abstracts CMT)

3 See O S Kulagina and I A Mel'chuk, "Ma- chine Translation from French to Russian, " Vo- prosy Yazykoznaniya, 1956, No 5; T N Mo- loshnaya, "Some Problems of Syntax in Connec- tion with Machine Translation from English to Russian, "Voprosy Yazykoznaniya, 1957, No 4

The theoretical basis for the isolation of typi-

cal sentence structures was the concept of the

syntagma (according to de Saussure) or of the

construct (according to Fortunatov) Machine

translation, however, requires a certain modi-

fication of this system In the structural syn-

tactic analysis proposed by the author, T N

Moloshnaya, of the English-Russian algorithm

worked out at MIAN, constructs consisting not

only of two members but also of many members

(constructions with an absolute participle, etc.)

are isolated Such elementary structures were

called configurations They are composed of

words classified according to formal signs

The analysis consists in reducing each configu-

ration to its basic word, that is, shortening it

In this way, syntactical links are established be-

tween the words of a sentence Synthesis of the

Russian Sentence is made by means of substitut-

ing for it a given English configuration which

corresponds to the Russian configuration and

completing it with Russian words on the basis

of the data of the dictionary, more precisely, of

the Russian part of the dictionary, and on the

basis of the corresponding morphological rules

The dictionary for machine translation, as com-

piled at MIAN during work on the French-Rus-

sian algorithm consists of two parts: (1) the

foreign, containing the words of the given lan-

guage (more precisely their stems, i.e the

graphically invariable parts of a word) with their

corresponding tags indicating part of speech, id-

iomatic relationships, government by preposi-

tion and grammatical characteristics and (2),

the Russian, containing Russian stems and the

corresponding information about them The Rus-

sian part of the dictionary is independent of the

foreign part; so it may be used in translating

from various languages The rules for the mor-

phological form of a Russian word are also inde-

pendent of the language from which the transla-

tion is made

The significance of the MIAN English-Russian

algorithm lay in the fact that in contrast to all

preceding algorithms in which the analysis of

the text under translation was realized in terms

of a translation into Russian (a category of the

Russian language was ascribed to a foreign

word), in T N Moloshnaya's algorithm the

structural-grammatical analysis of an English

sentence proceeded, in principal, independently

of the language into which the text was being

translated This is extremely important, for

an independent analysis opens the way for the

realization of machine translation not only from

one concrete language to another, but also from

many languages to many others

Several scientific groups are now working a- long this path opened up by the efforts of the MIAN Group In the division of applied linguis- tics of the Institute of Linguistics of the USSR directed by A A Reformatsky, rules for the analysis and synthesis of a text and an abstract system of lexical and syntactic correspondences between various languages are being worked out independent of a translation into a concrete lan- guage by I A Mel'chuk All of this should al- low us to do machine translation from several languages into several other languages (the mod-

el of such an intermediary language is being made on the basis of an analysis of Russian, English, Chinese, French, and Hungarian) Syntactic analysis lies at the basis of the trans- lation system being developed by I A Mel' chuk — morphological data are employed only as auxiliary data in the establishment of configura- tions, i.e in bringing out the relationships be- tween words in the source language and the ex- pression of these relationships by means of the target language

In this connection one should mention the re- search on the isolation and cataloguing of the sys- tem of relationships in the Russian language car- ried out in close collaboration with I A Mel'chuk

in the Laboratory of Electrical Modelling of the Ail-Union Institute of Scientific and Technical Information of the State Scientific-Technical Committee in the Soviet of Ministers of the USSR and of the Academy of Sciences of the USSR(LE)

In Russian mathematical texts the workers of this laboratory, Z.M Volotskaya, E V Paducheva,

I N Shelimova, and A L Shumilina isolated and described about 200 syntagmas (two-membered constructs in a subordinate relationship) which are essential in both the analysis and the syn- thesis of a Russian sentence

A substantial contribution to the theory of translation algorithms and their programming was made by O.S Kulagina (MIAN) She de- veloped a system of so-called elementary oper- ators of the simplest steps of which any trans- lation process may consist and of programs cor- responding to these steps As a result, signifi- cant generalization and standardization in the process of making algorithms can be attained, all of which allows us to pose the problem of automation of the programming of algorithms and then the problem of their automation and construction

MT in the Soviet Union 97

The Experimental Laboratory of Machine

Translation of the Leningrad State University

(ELMP) under the directorship of N.D.Andreyev

is also endeavoring to realize the idea of develop-

ing completely independent methods of analysis

and synthesis and of some abstract logical sys-

tem making it possible to go from analysis to

synthesis, i.e a system that will serve as an

intermediary language In this laboratory ex-

tensive material from various linguistic sys-

tems is being investigated; Indonesian-Russian,

Arabic-Russian, Japanese-Russian, Burmese-

Russian, Norwegian-Russian, English-Russian,

Spanish-Russian and Turkish-Russian algorithms

are being developed The intermediary lan-

guage which N D Andreyev is attempting to

create is an artificial language constructed by

averaging the phenomena of various languages

It is regarded as a material language with its

lexicon, its morphology, and its syntax, but

with the one peculiarity that it consists of sym-

bols * In the selection of the categories at the

basis of his symbolization, N D Andreyev con-

siders the most frequent phenomena and also

the international prestige of each language.4

The system of signs developed in ELMP for

the recording of the intermediary language can

be used also for the recording of information in

information machines

Along with work on the algorithms of machine

translation from foreign languages into Russian

and from Russian into foreign languages being

conducted in the Gorki State University, the fol-

lowing algorithms are being elaborated: Arme-

nian-Russian and Russian-Armenian (in the Com-

putation Center of the Academy of Sciences of

the Armenian SSR), Georgian-Russian and Rus-

sian-Georgian (in the Institute of Automation

and Telemechanics of the Academy of Sciences

of the Georgian SSR)

In the First Moscow State Institute of Foreign

Languages (I MGPIIYa) where under the direc-

torship of I.I.Revzin theoretical investigations

of the problems of machine translation and of

related problems of linguistic theory of trans-

lation and methodology of foreign language teach-

* Translator's note: The author obviously

means symbols different from the conventional

symbols of language

4 N D Andreyev, "Machine Translation and

the Problem of an Intermediary Language," Vo-

prosy Yazykoznaniya, 1957, No 5

ing have been carried out, the elaboration of Russian-English, Russian-French, and Russian- Spanish translation algorithms for foreign policy texts has begun At the Institute, the Machine Translation Society has been created at whose meetings theoretical problems are discussed and an exchange of ideas about the practical problems of the compilation of the algorithms takes place In the bulletin published by the So- ciety are published both theoretical and experi- mental work connected with the problem of ma- chine translation In May, 1958, the Society convened the First All-Union Conference on Ma- chine Translation Seventy-nine institutions were represented at the conference, including twenty-one institutes of the Academy of Sciences

of the USSR and eight institutes of the Academies

of Science of the Union Republics, eleven univer- sities, and nineteen other institutions of higher learning in the country Linguists, mathemati- cians, and technicians took part in the work of the conference At the plenary and sectional meetings of the conference there were discus- sions of more than seventy reports and communi- cations devoted to general linguistic problems arising in connection with the use of language in present-day automatic devices as well as to spe- cial problems of construction of algorithms for machine translation 5

The central problem now confronting linguists working in the field of machine translation is that of the methods of formal description of lin- guistic structures Structural methods, parti- cularly the methods elaborated by descriptive linguistics, offer much of value for the formal description of language — it was not by accident that the work of Fries in the structure of the English language proved useful in working out English configurations It has become clear, however, that these methods are inadequate for the formal description of language to the ex- tent that this is demanded in automatic transla- tion In connection with this a search for means

of applying mathematical methods to the analys-

is of language was begun With this in mind the Department of Philology of the Moscow State Uni- versity initiated a seminar on mathematical lin- guistics in 1956, joining mathematicians and lin- guists under the direction of P.S Kuznetsov, V V Ivanov, and V A.Uspensky Here, as well as at the meetings of the Machine Translation Society the idea, suggested by Academicians A N Kolmogorov and A A Lyapunov, of applying the methods of mathematical logic and of set

5 See Abstracts CMT, M., 1958

theory to the study of language was discussed

Thus, for example, A N Kolmogorov's idea

about the possibility of a strict formal definition

of the category of case (the work of V.A Uspens-

ky and, in part, also of R L Dobrushin) was

expounded and developed It is interesting to

note that eight cases can be counted in the de-

clensional system of the Russian substantive

according to this definition

A method for defining grammatical categories,

worked out by a student of Professor Lyapunov,

O S Kulagina (MIAN), was discussed at the se-

minar This method of definition allows one to

obtain, independently of the concrete features

of the language, a classification of words and a

determination of their syntactic relationships

Language in this conception is regarded as a

set of elements — words, or more exactly —

word forms A finite number of words arrang-

ed in a definite order is called a sentence Cer-

tain sentences are assumed to be marked —

these are sentences constructed according to

the norms of the given language — others are

unmarked According to the criteria of mutual

substitutability of words in the marked sentences

the entire set of words is broken down into groups

of mutually equivalent words

In terms of this system a series of definitions

corresponding, in general, to certain tradition-

al morphological categories, for example, parts

of speech, was successfully obtained The ad-

vantage of this classification lies, however, in

the fact that it has been deduced on the basis

of an exact and strictly formal system of defi-

nitions It is particularly effective for languages

with a rather symmetrical system of word forms

(for example, French) In languages like Rus-

sian that do not possess this symmetry, the

method of defining a grammatical category pro-

posed by R L Dobrushin can be utilized

By making use of the criterion of equivalency,

the relationships between the classes of words

isolated are also determined Moreover, the

concept of configuration, mentioned earlier,

gets a more exact definition: a configuration is

defined by O S Kulagina as that combination

of not less than two words belonging to various

non-intersecting subsets, which can be reduced

to one element without any marked sentence con-

taining this configuration losing its marked quali-

ty Thus the combination of the words "thick

book" in the sentence "the thick book lies on

the table" can be reduced to the element "book"

or can be replaced by the element "thing" or

the element "it" without the sentence ceasing to

be marked The isolation of the configurations allows one to determine the syntactic structure

of the sentence

The set-theory concept of language is strictly deductive and formal This is just what deter- mines its importance both for general linguis- tics and for machine translation Naturally the formal description of language is possible only

to a limited extent Thus, the concept of the marked quality of sentences, without which it

is impossible to determine the equivalence of elements and configurations of a language, will have little effect if it is extended to all function-

al areas of language But in a limited sphere

of language — and machine translation at the present time is being considered only within the limits of scientific and technical prose — this concept is sufficiently exact and effective Thus, all sentences in a given language which are met

in a given field of scientific literature can be considered marked

The set-theory conception of language is im- portant in yet another respect Since it allows

us to construct and investigate a grammatical model, i.e a simplified analog of actual lin- guistic relationships, this theory opens one of the possible ways for logico-semantic investiga- tions of language In this connection we should point to the ideas of V V Ivanov about the pos- sibility of applying mathematical methods to the definition of the lexical meaning of words I note that, contrary to wide-spread opinion, the theory of machine translation is not limited to the investigation of language in its formal as- pect alone The search for methods of objective, precise description of the system of meanings

in language has begun

If it is true that complete formal description

of an actual language is hardly accessible, that

it is necessary to attain only formal approxima- tions to actual language, then a statistical eval- uation of the probability of this approximation acquires special importance 6 On the other hand, certain phenomena of language do not yield, for the time being, to structural descrip- tion and can be formally described only statisti- cally

6 See V A Uspensky, "Conference on the Statistics of Speech," Voprosy Yazykoznaniya,

1958, No 1, p 173

MT in the Soviet Union 99

The quantitative aspect of linguistic phenomena,

both lexical and grammatical, has been consider-

ed, as a rule, in all the algorithms formulated

One should point particularly to the statistical

investigations carried out on Russian language

material in the Laboratory of Electrical Model-

ing I have already mentioned the cataloguing

of Russian syntagmas This work was accom-

panied by a statistical investigation of the lan-

guage of Russian mathematical texts The re-

sults of this work conducted by I A Mel'chuk,

T N Moloshnaya, A L Shumilina, Z M

Volotskaya, and I I Shelimova, were, along

with other works, announced at the conference

on the statistics of speech convoked in October

1957 by the Section of Speech of the Commission

on Acoustics of the Academy of Sciences of the

USSR and by Leningrad University This work

is of interest not only in a practical respect

Its value consists in a true solution to the prob-

lem of combining statistical and structural me-

thods: a count of linguistic elements was car-

ried out by the authors on the basis of a clear-

cut definition of such concepts as "syntagma",

"type of syntagma", etc As I I Revzin show-

ed in his report presented at the conference

mentioned, the correlation of structural and

statistical methods has a two-sided nature: sta-

tistics aids in specifying the structure of lan-

guage and an exact structural definition of units,

the number of which are counted, insures the

proper conduct of the statistical investigation

A frequency count of dictionary units is im-

portant not only in connection with machine

translation No longer speaking about statisti-

cal investigations of problems of general and

particular linguistics 7, which have already be-

come traditional, we shall point to recent works

connected with the use of language in various

devices for the storage, processing, and trans-

mission of information In reference to the Rus-

sian material we can call attention to the use of

methods of machine translation for the coding

of telegraphic and telephonic messages

It has been established (V I Grigor'ev and

G G Belonogov) that the size of a telegraph

message in Russian can be diminished by 3-4

times if the telegraphic communication is trans-

lated from a letter code into a dictionary (lexi-

cal) code Statistical investigations have shown that in the case of such coding 4, 000 common words would be sufficient in order to insure the transmission of 97.5 percent of a general-lan- guage text

The problem examined here is connected, for the most part, with an analysis of the text under translation For the Soviet specialists the ela- boration of effective methods for analysis pre- sented special difficulties: they dealt primari-

ly with morphologically poor languages It would be erroneous, however, to assume that the synthesis of the Russian sentence did not present any serious difficulties to them By way of illustration we may cite the difficulties arising in the synthesis of Russian aspectual forms, inasmuch as the category of aspect per- meates the entire Russian verbal system

Here two problems of principle arise In the first place, it is necessary to find a principle

of classification of Russian verbs which will al- low us to obtain for each verb in an absolutely regular way (by adding or taking away the same letters) all forms of the perfective as well as of the imperfective aspect Such work was done by

Z M Volotskaya (LE), who obtained three break- downs of the whole Russian verbal complex ac- cording to method of formation: a) of present tense forms; b) of past tense forms; and c) of the perfective stem from the imperfect stem 8

In the second place — and this task is much more difficult — it is necessary to work out the rules for the choice of one or the other aspectu-

al form Inasmuch as the tendency towards car- rying out the operations of synthesis independent-

ly from those of analysis has already been noted, these rules must be constructed on the basis of contextual data, considering, for example, the presence in the sentence of adverbs, the charac- ter of the combination, etc In a series of cases one must limit oneself only to a probable solu- tion, based on statistics

The problem of machine translation from Rus- sian, of course, occupies Soviet investigators less than the problem of translation into Russian But investigative work connected with the analy- sis of the Russian sentence has already begun (chiefly in the Laboratory of Electrical Modeling, the Division of Applied Linguistics of the Insti- tute of Linguistics of the Academy of Science of the USSR and in ITM and VT) From the point

of view of general linguistics the work reveal-

7 In this connection one should recall the

works in the statistical investigation of Russian

literary works, carried out in the 20's and 30's

by A I Peshkovsky, M Peterson, et al 8 See Abstracts CMT, p 87

ing the redundancy of certain categories of the

Russian language is most interesting Thus,

for example, the category of gender in the Rus-

sian verb, expressed only in the forms in -1 of

the singular of the past tense and of the condi-

tional mood, is redundant, unnecessary from

the standpoint of analysis It is clear (V N

Vinogradova, the Institute of Linguistics of the

Academy of Science of the USSR) that in scienti-

fic texts the number of verbs with the expressed

form of gender comprises from four to thirty per-

cent and that in the majority of sentences the

verb can be related only to the subject — the

only substantive in the nominative case Nor is

it necessary, in most cases, to consider the in-

flection of the Russian adjective and determine

the relationships of the adjective to the substan-

tive with which it agrees on the basis of the po-

sition of the adjective in the sentence (N N

Leont'eva and G H Vavilova, the Institute of

Linguistics)

Interesting also is the work on the determina-

tion of syntactic links for the preposition-case

groups of the Russian language (I N Shelimova)

and also the work on the elaboration of the syn-

tactic links for formulas in Russian mathemati- cal texts (M M Langleben) — by formulas the author means all elements not found in the ma- chine dictionary during the processing of the text (mathematical formulas, foreign-language cita- tions, surnames, etc.)

For the analysis of a Russian sentence it is necessary to characterize the marks of punctu- ation Only in such a way can one find the lim- its of a simple clause within a sentence, isolate its similar members, aid the further clarifica- tion of the co-relationships of the individual parts of a sentence with complex punctuation, de- termine a group of similar members T N Nikolayeva (ITM and VT) conducted an analysis

of polysemantic marks of punctuation (comma, dash, colon) in Russian9

Thus the realization of machine translation presupposes serious theoretical investigations, which, in turn enrich the problems of general and applied linguistics

9 See Abstracts CMT, pp 104-107